For the first time since America's twin Viking landers touched down on the Red Planet in 1976, NASA has two working spacecraft on the surface of Mars. The space agency has completed successfully five out of its six attempts to land on the Red Planet. The rover Spirit was launched from Earth on June 10, 2003, and landed on Mars on January 4, 2004, at Gusev Crater, which may be an ancient lake. Its twin, Opportunity, was launched on July 8, 2003, and landed on Mars on January 25, 2004, at Meridiani Planum, which has minerals associated with water. On March 2, 2004, NASA announced that the rovers had confirmed liquid water once flowed on Mars.background on the rovers »»

A NASA artist imagines the Mars exploration rovers Spirit and Opportunity look like this on the Red Planet. Spirit landed in Gusev Crater on January 4, 2004. Opportunity landed on Meridiani Planum on January 25, 2004.click image to enlarge - NASA JPL

Spirit took this snapshot of its 'empty nest' as it looked back at the Columbia Memorial Station on Gusev Crater. Two miles in the distance are the Eastern Hills, top right. click image to enlarge - NASA JPL

» January 31, 2004:Spirit's Mössbauer spectrometer reveals the kinds of iron-bearing minerals in a rock. Analysis of readings by that spectrometer as well as photos from the rover's microscopic camera show the rock Adirondack is volcanic material. It is a hard, crystalline rock holding the minerals olivine, pyroxene and magnetite. That composition is common in volcanic basalt rocks on Earth. One JPL team member pointed out that, if you hit the crystalline rock with a hammer, it would ring. The University of Mainz in Germany provided Spirit's Mössbauer spectrometer.
Picture: Mössbauer Spectrometer

Next, Spirit will use its rock abrasion tool to grind off the weathered surface from a small area of Adirondack's face to inspect its interior.
Picture: Adirondack

» January 30, 2004: The JPL team continues to nurse Spirit back to health, suggesting the possibility of resuming full operations soon. They asked the rover to send pictures and the data on the rock Adirondack from the Moessbauer spectrometer and the alpha particle X-ray spectrometer stored in memory since the communication and computer problems started on January 22. The engineers still don't have total knowledge of what went wrong with Spirit, so they may decide to reformat the rover's flash memory in the next few days. Next will be health checks on the camera mast and an actuator motor for a periscope mirror of the miniature thermal emission spectrometer. The robot arm with the Moessbauer spectrometer at the tip still is extended out to the rock Adirondack.
Picture: Moessbauer at Adirondack

» January 29, 2004:Spirit surely seems to be feeling better. The rover resumed using its high-gain antenna. It sent home its first picture in a week. The image from the rover's front hazard identification camera shows the robot arm extended out to the rock Adirondack. As instructed a week ago, the Moessbauer spectrometer is touching the rock. That spectrometer identifies the minerals in rocks and soils. Spirit should be back in working order soon so it can resume exploring around its landing area.
Picture: Moessbauer at Adirondack

» January 28, 2004: Three martian hills near Spirit have been named in memory of the American astronauts killed in the tragic Apollo 1 launch pad fire on the 37th anniversary of their tragic deaths.

Virgil I. "Gus" Grissom, Edward H. White 2nd and Roger B. Chaffee were killed January 27, 1967, in a fire as they sat in an Apollo capsule on the launch-pad during a ground test at Cape Canaveral. At that time, there was a rush to beat the Russians to the Moon by the end of the 1960s. The first manned test of the then-new powerful Saturn 1B rocket was to be February 21, but it didn't happen. On January 27, 25 days before their scheduled lift-off, Grissom, White and Chaffee were practicing in Apollo 204 during a simulated countdown on the launch pad when fire broke out in the capsule. The Apollo 204 capsule later was renamed Apollo 1.

The hills around Spirit's landing site:
·Grissom Hill is 4.7 miles southwest·White Hill is 7 miles northwest·Chaffee Hill is 8.9 miles south-southwest

NASA administrator Sean O'Keefe said, "Gus, Ed and Roger's contributions, as much as their sacrifice, helped make our giant leap for mankind possible. Today, as America strides towards our next giant leap, NASA and the Mars Exploration Rover team created a fitting tribute to these brave explorers and their legacy."
Apollo 1 Hills:PictureMap

» January 27, 2004: Engineers continue to be successful in restoring Spirit to good health. The rover obeyed commands and transmitted helpful information to the JPL team. The engineers found a way to stop Spirit's computer from resetting itself about once an hour by putting the spacecraft into a mode that avoids use of flash memory. The rover also has random-access memory, which cannot hold information during the rover's overnight sleep. The JPL team plans to erase a large number of files from flash memory. They had been stored there during the spacecraft's cruise from Earth to Mars. Killing the old files will reduce the computer software's work of managing flash memory files. Flash memory is a non-volatile kind of computer memory that can be erased and rewritten as needed and retains its data after power is turned off.
JPL late news

» January 26, 2004: Engineers are encouraged to find Spirit's flash memory hardware functional. They think the rover's recent problem has been in software that manages files for the flash memory. The rover project manager at JPL likened Spirit to a patient "well on the way to recovery." Flash memory is a non-volatile kind of computer memory that can be erased and rewritten as needed and retains its data after power is turned off.

NASA describes the rover's computer as comparable to a high-end laptop. The main difference: Spirit's computer memory was built to tolerate the extreme radiation environment of outer space and to safeguard against power-off cycles so its programs and data will remain intact and not be erased accidentally when the rover shuts down at night. Spirit has 128 megabytes of volatile random-access memory (RAM) and 256 megabytes of non-volatile flash memory. That's roughly equivalent to the memory in an ordinary home computer.

JPL is the Jet Propulsion Laboratory at Pasadena, California, a division of the California Institute of Technology. It manages the Mars Exploration Rover project for NASA's Office of Space Science at Washington, D.C.
The Mars exploration rovers will explore the areas around their landing sites for evidence in rocks and soils of environments that were watery and suitability for sustaining life.
JPL late news

» January 25, 2004: NASA's Mars exploration rover Spirit is considered much healthier after engineers were able to communicate with it satisfactorily. Controllers successfully ordered the rover's computer to stop rebooting itself many times a day.

The JPL team thinks the problem is in the rover's two flash memories. Flash memory is a non-volatile kind of computer memory that can be erased and rewritten as needed and retains its data after power is turned off. It is known by such names as CompactFlash, SmartMedia, or Memory Stick when used in digital cameras and PDAs. Spirit has 256 megabytes of flash memory. Engineers bypassed the flash memory problem by commanding the rover to use its random-access memory instead. The rover obeyed the command by communicating for nearly an hour and going into sleep mode. They plan to command Spirit each morning not to use flash memory. Further examination confirmed that flash memory hardware was working, pointing the finger at file management software as source of Spirit's troubles.

The JPL team described Spirit as stable in power and temperature control. Even so, Spirit may not be able to continue its drive across the surface of Mars for more than a week.
JPL late news

» January 31, 2004:Opportunity drove off of its landing platform onto the ground of the little crater in which it sits, giving the United States two working rovers on martian soil. Opportunity is in the center of a 72-ft.-wide, 10-ft.-deep crater. As it maneuvered three feet away from its landing platform, the rover looked back and snapped a photograph showing its wheel tracks in the martian dirt. Now, Opportunity can begin to record microscopic images and spectrometer readings of the soil close to the lander. Next week, the rover will drive northwest about 26 feet to an outcrop of bedrock.
Picture: Opportunity wheel tracks

» January 30, 2004:Opportunity is getting ready for a drive this weekend. The landing platform pulled part of an airbag under its backside so its reinforced fabric ramp on the front would tilt down to the martian surface making it easy for the rover to drive off. The rover retracted a lift mechanism on its bottom. Next, Opportunity will lower the middle pair of its six wheels and release a latch that has been holding its robot arm.
Animation: rover rising

» January 29, 2004: Unfolding its front wheels and locking them into position, Opportunity prepared for a Sunday drive. While untold millions of humans back home on Earth are watching the Super Bowl football game, Opportunity may make the all-important ten-foot drive off of its landing platform onto the martian surface on February 1.

On the 18th anniversary of the Challenger tragedy, Opportunity's landing site on the vast flatland of Meridiani Planum was named Challenger Memorial Station in honor of the space shuttle Challenger's final crew. The seven Challenger crew members were killed when the shuttle exploded during launch on January 28, 1986.
Picture: Challenger Memorial Station

» January 28, 2004:Opportunity remains on its landing platform looking around at the martian ground rich in hematite over an underlying bed of light-colored layered rock. The rover is using its high-gain antenna successfully. The JPL team noted the rover is losing some if its battery charge each night, maybe from an electric heater in the robot arm shoulder joint. A thermostat turns on the heater when the air temperature falls at night, even though the heater is not needed if the arm is not in use, Controllers on Earth, who have been unable to use a switch designed to override the thermostat, are trying to figure out what might result from the power drain. They hope to come up with a workaround.
Picture: hematite sample at JPL

» January 27, 2004: The three scientific sensing instruments on Opportunity's robotic arm passed health tests. They will be used for up-close examination of rocks and soil. The instruments are the microscopic imager, the alpha particle X-ray spectrometer for determining what elements are present, and the Moessbauer spectrometer for identifying minerals containing iron. Photos sent by Opportunity show dark soil with bright spots where the lander bounced and rolled. The surface texture inside the small crater where the rover sits on its landing platform seems to be a mix of reddish and charcoal-colored granules with bedrock outcroppings.
Pictures: more bedrock outcroppings

» January 26, 2004:Opportunity is in a shallow 66-ft.-wide impact crater about half a mile from a larger 500-ft. crater on the Meridiani Planum. Using a golf analogy, the rover's principal scientist called it a "300-million mile interplanetary hole in one." Visible in the small crater with the rover is a large outcropping of bedrock. The NASA JPL team is excited about the rover being in a crater because they will be able to examine what's beneath the martian surface without digging.
Picture: rover in a crater

Planetary scientists had wished for a landing site with a surface layer rich in hematite over an underlying bed of light-colored layered rock. They got what they wished for. The small crater has both – soil that looks at first glance to be hematite and the exposed outcropping of layered lighter rock. The bigger crater nearby should provide access to even deeper layers. Crystalline hematite is a mineral, which usually forms in the presence of liquid water. One theory holds that hematite may have formed in a long-lasting lake or in a volcanic environment.

Engineering data relayed from Opportunity by NASA's Mars Odyssey orbiter spacecraft, indicated the rover is in excellent working order. Opportunity now will spend a week or more getting ready to drive away. Then the rover will drive off its landing platform, examine the soil around the lander, and drive over to examine the bedrock outcrop. After that, the rover may roll up and out of the small crater and head for the larger crater.
Picture: outcropping of bedroock

» January 25, 2004: NASA's Mars exploration rover Opportunity landed on target on the surface of the Red Planet at 0505 January 25 UTC. Protected in its cocoon of airbags, the rover bounced along the martian plain and rolled nearly a mile across the surface ending up in a small crater. It came to a stop on its side around 0510 UTC. Radio signals from Opportunity were received on Earth by NASA's Deep Space Network antennas at Goldstone, California, and Canberra, Australia, as well as by the Stanford University radiotelescope in California. Signals also were picked up by NASA satellites orbiting above the planet and relayed to Earth. The Mars Global Surveyor orbiter heard the rover as it was dropping to the ground.

Opportunity, a twin to Spirit, landed in the afternoon at Meridiani Planum on the opposite side of Mars some 6,600 miles away from where Spirit had landed 21 days earlier. Unlike the reddish dust around Spirit, the rover Opportunity touched down on a flat, relatively dust-free plain rich in a mineral called gray hematite, which paints the ground a kind of charcoal brown color. Near the lander was an outcropping of bedrock, the first ever seen on Mars by explorers from Earth. Opportunity will roll off of its landing platform in about ten days.

For the first time since America's twin Viking landers touched down on the Red Planet in 1976, NASA has two working spacecraft on the surface of Mars. NASA now has completed successfully five out of its six attempts to land on the Red Planet. Opportunity was launched from Earth on July 8, 2003.
Opportunity's first pictures

» January 24, 2004: The rover Opportunity will land tonight at Meridiani Planum on the opposite side of Mars some 6,600 miles away from where Spirit landed 21 days earlier. The lander is on a correct course for entry, descent, and bounce-down on the martian plain. Unlike the reddish dust around Spirit, the twin rover Opportunity will touch down on a relatively dust-free plain rich in a mineral called gray hematite, which paints the ground a kind of charcoal gray color. The only other time NASA has had two working spacecraft on the surface of Mars was in 1976 with the twin Viking landers. Here are Opportunity's landing times tonight:

9:05 p.m. January 24 PST Pacific Standard Time, local at NASA JPL
12:05 a.m. January 25 EST Eastern Standard Time, Washington DC
0505 January 25 UTCcoordinated universal time or GMT

Opportunity will plunge into the martian atmosphere at 12,000 mph about six minutes before its landing time. When it hits the surface of the planet, Opportunity will bounce a number of times just as Spirit did three weeks ago. Protected inside a cocoon of airbags, Spirit had bounced high off the ground 28 times and rolled nearly a mile across the surface.

» January 24, 2004:Spirit did not go to sleep despite two commands from controllers to do so. However, it surprised the JPL team with a large 73-megabit packet of engineering data sent via the Mars Odyssey orbiter. Previously, Spirit had not communicated through Odyssey for two days. Sorting through the received data, the JPL team found a report on the power subsystem and several frames of fillers, which are intentionally uninformative random numbers. The information was troubling because it showed Spirit's batteries were draining. If the JPL team couldn't regain control quickly of the solar panel battery charging system, the rover's batteries would run down in just a few days. After analysis of the received data, the JPL controllers were able to reset Spirit's computer and put the rover into what they called "cripple" mode bypassing software problems. The JPL team put the problem in medical terms when they proclaimed the rover's condition upgraded from critical to serious. Spirit may not be able to continue its drive across the surface of Mars for as long as three weeks. JPL late news

» January 23, 2004:Spirit phoned home today. NASA reported that the JPL flight team in California received engineering data from the rover during three communications sessions lasting 10, 20 and 15 minutes. Spirit responded to a command sent via the agency's Deep Space Network antenna near Madrid, Spain. Controllers are studying the data for clues as to what caused the rover's odd behavior over the last two days. Among issues facing controllers is the apparent crash of Spirit's computer. Its software seems to have rebooted the computer more than 60 times in the past three days. It's likely that replacement software will have be uploaded to the rover's system by radio from Earth. In addition, a motor may have been moving a mirror on the infrared spectrometer when the rover's problem started, so data about that hardware will have to be examined. One scary problem seen in the data – Spirit's batteries are being discharged unexpectedly and could run down in a few days unless the JPL team can regain control.

Meanwhile, the other American rover, Opportunity, is racing at more than 12,000 mph toward its scheduled landing at Meridiani Planum on January 25. The landing should occur at:

9:05 p.m. January 24 PST Pacific Standard Time, local at NASA JPL
12:05 a.m. January 25 EST Eastern Standard Time, Washington DC
0505 January 25 UTCcoordinated universal time or GMT

Meridiani Planum is halfway around the planet from Gusev Crater, where its twin, Spirit, landed. The soil at Meridiani Planum has an ancient layer of hematite. On Earth, that iron oxide almost always forms in an environment containing liquid water. The outcropping of gray hematite on the martian plain is the size of the state of Oklahoma on Earth. Meridiani Planum

» January 22, 2004:Spirit sent a simple radio signal today acknowledging it had received a transmission from Earth. However, the NASA JPL team is still trying to figure out what has caused the rover to send no photos or science data yesterday and today. Spirit did send a radio signal via NASA's Mars Global Surveyor orbiter yesterday, although the transmission did not include any photos or data. Spirit did not make radio contact with NASA's Mars Odyssey orbiter yesterday or today. The rover also did not send a signal at a pre-set time when it should have recognized a communication problem. JPL late news

» January 21, 2004:Spirit started the day by acknowledging a signal from Earth, but then did not send any science or engineering data for the rest of the day. Controllers weren't sure what was up, but recalled similar silences during the Pathfinder mission in 1997. Later, NASA reported that rain and lightning at a Deep Space Network radio dish antenna in Canberra, Australia, prevented it from sending commands to the rover. Hearing nothing, Spirit had gone to sleep. Scientists had to postpone use of the rover's RAT (Rock Abrasion Tool) to grind into the rock "Adirondack." The NASA JPL team hoped the rover would communicate via the Mars Global Surveyor or the Mars Odyssey orbiters tonight. If not, when the rover wakes up tomorrow, the team will try to communicate directly from Earth via the DSN antenna. JPL late news

» January 20, 2004: The rover Opportunity is just days away from landing at Meridiani Planum on January 25, while the rover Spirit is using its microscope and two up-close spectrometers on the rock "Adirondack." Meanwhile, soil analyzed earlier by Spirit is puzzling scientists. The Moessbauer alpha particle X-ray spectrometer, which identifies iron minerals, and the microscopic imager, examined a patch of soil just off the landing platform. The spectrometer detected the mineral olivine, a shiny green material commonly found in lava on Earth. Not much was disturbed as the spectrometer was pressed onto the patch. Could sulfates and chlorides, left behind by evaporating water, bind the particles together? The salts also could have come from volcanic eruptions. Scientists believe many Mars minerals contain iron. The rover's alpha particle X-ray spectrometer, which reveals elements in soils and rocks, found the soil was mostly silicon and iron. It also found significant levels of chlorine and sulfur. Traces of zinc and nickel were found. soil patchrobot arm reaches out to rock

» January 19, 2004:Spirit motored across the sandy terrain at Gusev Crater to a football-sized rock NASA named "Adirondack," which has a flat surface relatively free of dust. The rover will grind into the surface of the rock to expose fresh material. Spirit took 30 minutes to drive ten feet to the rock. The Native American word Adirondack, from the New York mountains, is interpreted by NASA as "They of the great rocks." Adirondack

» January 18, 2004: The Mars exploration rover Opportunity is just a week away from landing at Meridiani Planum on January 25. Bounce-down on the Red Planet's surface should occur at about:

9:05 p.m. January 24 Pacific Standard Time (PST) local time at NASA JPL
12:05 a.m. January 25 Eastern Standard Time (EST) Washington DC time
0505z January 25 UTCcoordinated universal time or GMT

Meanwhile, NASA controllers continue to operate the rover Spirit on the wind-swept rock-strewn surface of Gusev Crater. The crater is about the size of the state of Connecticut on Earth. Gusev Crater

» January 16, 2004: Working near its landing platform, Spirit stretched its arm down toward the martian soil. Then the rover used its Microscopic Imager – one of four science tools at the end of the arm – to snap the highest resolution photograph of the martian surface to date. Like a geologist's hand lens, the Microscopic Imager allows close up views of the soil and rocks. photo of extended arm

» January 15, 2004:Spirit motored off of its landing platform onto the martian soil. It traveled about three feet away from the platform at nine miles per hour, and sent home a photo of its tracks in the red dust. photo of wheel tracks in the dust

» January 13, 2004: Controllers on Earth plan to send Spirit off of its martian landing platform January 15 to look more closely at rocks strewn about its landing site. Then it will roll some 820 feet away to investigate a 656-ft.-wide crater. The depression probably was formed eons ago when a meteorite hit the surface. Spirit might find out what had been as deep as 98 feet below the surface of Mars by analyzing material thrown out of the crater by the impact. Then, Spirit will roll on towards the so-called "Eastern Hills" about two miles away. It's not clear how close to the hills it can go since the rover was designed to travel only 2,000 feet from its landing site. If it doesn't go all the way, the rover still might find rocks that originated in the hills, which could be compared with rocks found around the Gusev Crater landing site. travel itinerary

» January 9, 2004: NASA JPL controllers now expect Spirit to drive of its landing platform on January 16 or 17. The ramp straight ahead of Spirit is blocked by the air bags that cushioned the rover's landing. To leave the platform, Spirit now will turn 120 degrees to roll along a ten-foot ramp on its right to the ground. Getting ready to roll, the rover stood up on the landing platform and extended its front wheels. Meanwhile, even before driving away, Spirit has spotted nearby minerals, called carbonates, which may indicate liquid water once existed there. More data is required before scientists will know for sure. Spirit sent data showing the warmest temperature on the ground around the lander is about 41 degrees Fahrenheit (5 degrees Celsius) and the coldest is about 5 degrees Fahrenheit (-15 degrees Celsius).

» January 8, 2004: NASA JPL engineers are trying to figure out what to do about two sections of the lander's cushioning air bags, which are blocking the ramp straight ahead of Spirit. The worry is that the woven polymer fiber airbags might snag the rover's robotic arm or the solar panels. The engineers tried unsuccessfully to lift the ramp and retract the air bags. JPL late news

» January 7, 2004: The Mars exploration rover Opportunity continues flying toward a landing at Meridiani Planum on January 25. Bounce-down on the Red Planet's surface should occur at about:

9:05 p.m. January 24 Pacific Standard Time (PST) local time at NASA JPL
12:05 a.m. January 25 Eastern Standard Time (EST) Washington DC time
0505z January 25 UTCcoordinated universal time or GMT

Meanwhile, NASA controllers plan to drive the rover Spirit off of its landing pad and onto the wind-swept rock-strewn surface of Gusev Crater on January 14.

» January 5, 2004: Scientists peering at Spirit photos at NASA's Jet Propulsion Laboratory, Pasadena, California, noticed a shallow depression in the relatively flat ground around the rover and named it Sleepy Hollow. The shallow bowl in the martian surface is 30 feet across and lies some 40 feet north of Spirit. It probably will be one of the first destinations when the six-wheeled rover rolls off its landing craft in about a week in search of clues to the past environment of Mars.

» January 4, 2004: The lander retracted its airbags, deployed its petals and solar arrays, raised its panoramic camera mast, and snapped a first photograph of itself on the martian surface. It then found the Sun with its panoramic camera and calculated how to point its main antenna toward Earth by knowing the Sun's position.

» January 4, 2004: NASA's Mars exploration rover Spirit landed exactly on target on the surface of the Red Planet at 0435 January 4 UTC. The rover, protected in a cocoon of airbags, bounced high off the ground 28 times and rolled nearly a mile across the surface. It came to a stop around 0445 UTC. Spirit's radio signals were received on Earth by NASA's Deep Space Network antennas at Goldstone, Calfornia, and Canberra, Australia, as well as by the Stanford University radiotelescope in California. Spirit's signal also was picked up by NASA's Mars Global Surveyor satellite orbiting above the Red Planet and relayed to Earth. first pictures from Spirit

» January 3, 2004: The Mars rover Spirit is expected to land tonight on the Red Planet. Navigators have directed the spacecraft so close to a bull's-eye that mission control skipped two optional maneuvers before arrival at Mars. Meanwhile, the rover twin Opportunity continued to fly toward a January 25 landing on Mars. JPL late news

» January 2, 2004: The Mars rover Spirit is just one day away from landing on the Red Planet. After a trip of seven months across some 300 million miles, the golf-cart sized rover is screamin' toward the martian atmosphere at more than 12,000 mph. If all goes well...

at 7:04 p.m. January 3 PST, Spirit will roll over so its heat shield is forward for final approach.
7:04 p.m. January 3 Pacific Standard Time (PST) local time at NASA JPL
10:04 p.m. January 3 Eastern Standard Time (EST) local time at Washington DC
0304z January 4 UTCuniversal time or GMT

at 8:14 p.m. PST, The entry vehicle will separate from the cruise stage, shedding more than half of the traveling spacecraft.
8:14 p.m. January 3 Pacific Standard Time (PST)
11:14 p.m. January 3 Eastern Standard Time (EST)
0414z January 4 UTC

The 2003 Mars Exploration Rovers Spirit and Opportunity were in an international flotilla of interplanetary probes arriving at Mars at the end of 2003 and the beginning of 2004 – including Mars orbiters from Europe and Japan and a Mars lander from Great Britain: